MISSISSIPPI PHOSPHATES CORPORATION
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The Mississippi Phosphates Corporation (MPC) manufactured Diammonium Phosphate (DAP) fertilizer at its Pascagoula facility from the late 1950’s thru December 2014 when it declared bankruptcy. Pursuant to a July 2015 bankruptcy settlement, two trusts were created: an Environmental Trust and a Liquidation Trust.
The Liquidation Trust consists of the former 106-acre property where fertilizer production and operations were conducted. The Liquidation Trust includes the infrastructure (fertilizer production plants, commercial buildings, waterfront docks) and other valuable real estate. The purpose of the Liquidation Trust is to market and sell these assets of the former MPC facility.
The Environmental Trust was created to manage the liabilities of the MPC facility. This included $12 Million in funding to manage the West Gypsum Stack/East Gypsum Stack , daily water treatment activities and site stability operations. The East Gypsum Stack (EGS) contained > 750 Million Gallons (MGs) of water with acidic pH (≈2-3) and high levels of nutrients (phosphorus/nitrogen) that was contained in a series of ponds and ditches with very poor structural integrity. Because of the large footprint (350 acres) of acid generating material exposed in the EGS, one inch of rainfall produces about 9 MGs of impacted water that must be stored and subsequently treated before discharge to the bayou. An average of 2 million gallons per day (MGD) of water is treated via lime precipitation to prevent an uncontrolled release of untreated water to the adjacent Grand Bay Estuary Reserve on the east and Bayou Casotte on the west. Water treatment operations and facility maintenance costs are about $1 Million per month.
In January 2017, the State of Mississippi added $500,000 from the State’s Pollution Emergency Fund to the Environmental Trust. These additional funds were exhausted, and the Environmental Trust became insolvent on February 10, 2017. The EPA Region 4 Superfund Division then assumed financial responsibility of daily water treatment activities and site stability operations. As of April 2020, the cost of water treatment and site maintenance are approaching $50 Million (not including the $12 Million Trust).
In April 2018, the EPA Administrator signed an Action Memo that approved a 3 phase, $72 Million closure plan for the EGS that is designed to improve the quality and reduce the quantity of contact water and leachate that requires treatment.
What Has Been Done to Clean Up the Site?
The MPC facility ceased operations in December 2014 under Chapter 11 bankruptcy protection, leaving more than 700 million gallons of acidic contaminated wastewater stored at the facility.
EPA assumed control and funding of wastewater treatment operations on February 11, 2017, after the MPC Environmental Trust became insolvent.
Due to excessive rainfall totals during hurricane season, EPA discharged about 400 million gallons of partially treated wastewater during five emergency bypass events. Bypasses are intentional discharges of wastewater that are typically conducted because heavy rain is forecasted to exceed storage capacity of the on-site phosphogypsum stacks and waste water treatment system. Bypasses are closely monitored to prevent eutrophication and algal blooms which take oxygen from the water and can have impacts on fish and mollusks populations. No adverse impacts have been observed, and no further bypasses have been necessary.
EPA formally added the MPC Site to the Superfund National Priorities List and proposed a cleanup plan for portions of the MPC Site.
April 16, 2018
EPA released an updated Administrator’s Emphasis List of Superfund sites targeted for immediate and intense attention. The Emphasis List is part of the Superfund Task Force recommendations. The MPC site was later removed from the Emphasis List because the various goals and objectives were being achieved.
April 18, 2018
The EPA Administrator signed an Action Memorandum for $107.6 million to accelerate the cleanup of the former Mississippi Phosphates Corporation (MPC) Site in Pascagoula, Mississippi, including $71.6 million dollars for cleanup that will take place from 2018 through 2022, and $36 million dollars for ongoing wastewater treatment during the three-year cleanup period. EPA continues to treat 2-4 million gallons of contaminated water each day.
A Value Engineering (VE) study was conducted to compare traditional closure methods using liner and two feet of cover soil versus an innovative strategy that employs an engineered geosynthetic turf cover system. EPA selected geosynthetic turf in its final design because it is expected to save an estimated $6 million, including $4.6 million on construction costs and $1.4 million in operations and maintenance costs (since it does not need to be mowed, fertilized, etc.). An estimated 42,700 truck trips for hauling cover soil will be eliminated, thereby reducing the environmental carbon footprint of the closure work. The geosynthetic turf can be installed more quickly, resulting in fewer days of ongoing wastewater treatment at the site (which currently averages $50,000 per day, but will be reduced as each phase of stack closure is completed). Lastly, the turf cover system has proven to be more resilient to extreme weather conditions including drought cycles, UV degradation, heavy rains with concentrated flow, and hurricane force winds.
What Is the Current Site Status?
EPA continues to treat acidic wastewater at a rate of about two to four million gallons per day at a cost of about $1 million per month. The cost of water treatment and site stability operations are approaching $50 Million.
Closure of the EGS started on the western slope in Fall 2018 and is expected to be completed in the spring of 2020.
Closure of the southern slope started in during the winter of 2019, and is expected to be completed by the end of 2020.
Remaining closure work on the northeast slope and water return ditch is anticipated to continue through 2022. To date, an estimated $32 Million has been expended on EGS closure activities.
The Liquidation Trust has been actively marketing the 106-acre property to buyers with an interest in purchasing the MPC facility and redeveloping it for future use in accordance with state and federal environmental law. EPA Region 4, the U.S. Department of Justice, and the Mississippi Department of Environmental Quality have worked with multiple parties to help facilitate the sale and beneficial reuse of the property.
A Remedial Investigation/Feasibility Study and subsequent clean up on the Liquidation Trust property will be conducted once the scope of the future redevelopment work is determined.
EPA continues to develop a cleanup plan for other needed actions at the site.